' Salty' rice plant boosts harvests

British scientists are breeding a new generation of rice plants that will be able to grow in soil contaminated with salt water. Their work may enable abandoned farms to become productive once more, writes Sean Margrave.

 

more, writes Sean Margrave. Tim Flowers and Tony Yeo, from Sussex University's School of Biological Sciences, have spent several years researching how crops, such as rice, could be made to grow in water that has become salty.

 

The pair have recently begun a three-year program, funded by the Biotechnology and Biological Sciences Research Council, to establish which genes enable some plants to survive saline conditions. The aim is to breed this capability into crops, starting with rice.

 

It is estimated that each year more than 10m hectares of agricultural land are lost because salt gets into the soil and stunts plants. The problem is caused by several factors. In the tropics, mangroves that create swamps and traditionally form barriers to sea water have been cut down. In the Mediterranean, a series of droughts have caused the water table to drop, allowing sea water to seep in. In Latin America, irrigation often causes problems when water is evaporated by the heat, leaving salt deposits behind.

 

Excess salt then enters me plants and prevents them functioning normally, Heavy concentrations of minerals in the plants curb the process of osmosis and stop them drawing up the water they need to survive.

 

To overcome these problems, Flowers and Yeo decided to breed rice plants that take in very little salt and store what they do absorb in cells that do not affect the plant's growth. They have started to breed these characteristics into a new rice crop, but it will take about eight harvests until the resulting seeds are ready to be considered for commercial use.

 

Once the characteristics for surviving salty soil are known, Flowers and Yeo will try to breed the appropriate genes into all manner of crops and plants. Land that has been abandoned to nature will then be able to bloom again, providing much needed food in the poorer countries of the world.